Separable attachment-plug.



H. HUBBELL.

SEPARABLE ATTACHMENT PLUG.

APPLICATION FILED 114 111, 1911.

1,021,101 Patented Mar. 26, 1912 55 27 F g./ 28 I 2 9 lllllll WITNESSES: INVENTOR ATTORNEY "HARVEY :HUIBBELL, or zeamenroar, conunorrcun snra zaiann ATTACHMENT-PLUG.

specification of Letters latent. Patented 3131'. 26, 1912.

Application filed-May 11-, 1911. sci-m ne. 626,567.

, Jo (z-mam it may concern:

@130 is known that Lljlanvnv I'IUBBELL, a citizen of the United Stat-es,-res1dmg at Bridgeport, county of Fairfield, 'State of- S-Gonucctmut, l1a\-'e 1uve11ted an Improveiheutl inseparable Attaclnnent Plugs, of

which the 'following is a specificatin.

This invention has for its object-to sirris' plify, cheapen and to generally improve-the construction and operatmnof-sparable at I tachment plugs, to simplifythe :'iss 'ainbling,-

to perfect the insulation andv especiallyyto provide .a structurein whichthe. danger of a breakage shall be reduced to the minimum should. the plug as a whole" or t h 'e cap be drop ed. v VVlthth ese and otherobjects n view I have devised the novel separable attachment plug of which thefollowiiig -description in' 2 connection with the accompanying draw ng ,is aJspecification,reference characters be ng used to indicate-the several parts. p p

Figure 1- is a longitudinal section of the plug complete, the parts being in the assembled position;- Fig. 2. a transverse sect-ion on the line 2-2 in Fig. -1, looking in the direction of the arrows; Fig. 3 a'planview of the insulating guard disk detached; Flgyl f a section on the line in-Fig. 3 Fig. 5 a plan view of the base with the shell removed; and Fig. 6 is an elevation of the base with the shell removed.

l n 10 denotes the insulating base, 11 the screw shell; 19 the insulating cap and 13 the insulating guard disk.- 'The cap.is provided twith the usual centralhole lfl through which the wires (not shown) are passed and on its inner side with 'a recess1'5. I p

16 denotes binding screws and 17 contact 40. posts which are carried by, plates 18 rigidly secured in the recess. The contact-posts are slotted longitudinally as at 19 in order togive 'a spring. actionin engaging and are prov ded with circumferential: grooves 20 to receive bosses on the contact tubes.

The base has an external screw'thread 21 molded thereon which .is. engaged by the screw-shell in'the usual manner. For the base contacts, indicatedbv 22 and 23, I preferably use tubes which -iliein longitudinal- I holes 24 in thebase and are provided withinwardly projecting bosses. 25 which are adapted to pass over the heads, f the contact posts and to engage the groo es therein.

The bosses in the tubes-actatvrightangles '.the shell of the socket (not shown);

'to the planes of theslots in the contact posts.

The slot-s permit the posts to yield'slightly as the membersof the plug are moved together and to spring outward again when the bosses are seated in the grooves. Contact, serves a's.-; a "center contact at ya socket (not shown) and is carried by a bracket 26' held in place by a center screw .27. Thisjcontact lies wholly within one of the holes inthe base and is thus perfectly insulated from the screw shell by the base itself. Contact :23 is carried by a bracket 28" which rests upon a ledge 29 on the base and is engaged by a flange 30 on the screw shell to which-ibis" secured as by solder, a t35, I after the screw shell is in place to lock the screw=shell.-- The assembling is thus made very simple. (See Fig. 6 in connection with 'Fig. 1').- -The insulating guard disk is of greater dlameter than the base'and cap, is

carried-\by "the cap and lies between said members in the assembled position. 'This serves the double purpose of an insulating cover for the binding screws in the cap and also as a buffer to. protect the plug as a whole and the capwhen detached from breakageshohld it be dropped. The wires (not shown) act normally to prevent the outer face of the cap from striking should it be dropped and cause the blow-to be received by the guard disk, which is ofgreater diameter and is relatively non-breakable.

guard disk is in practice made of fiber and The. guarddisk is provided with holes 31 through which the contact posts pass and is retained in place by spring clamping plates 32 whichare recessed into the guard 'disk and are provided with corresponding holes through which the contact posts pass. These clamping plates are provided with central longitudinal-slots 33 which cross the holes for thecontact posts, the holes being made slightly smaller than the postsso that the arms of th'eplates will grip the posts. Theclam ing plates are shown as secured in place by ugs. 34 formed integral therewith which are passed through the guard disk andclamped on the under side.

The operation islthe same as usual withseparable attachment-plugs. The base is inserted in a socket; the screw shell engaging The insulating guard disk remains removably attached to the cap." Electrical connection is made by passing the contact posts into low gitudina-l holes 24.- in the base and moving" them forward until the grooves in the-posts are engaged by'the bosses onthe contacts 'in-the base.- The passage of the 'curent is from the screw shell through-bracket 28 and one of the contact posts to the correspondtactsare carried, one of said brackets being 20 ing binding "screw in the cap and returning;

through the other binding screw and contact post and through contact 23 and bracket 26 which serves as-a center contact for ng'age- 'ment with thekontact' of a socket (not. 'shown).

Having thus described my' invention I I- claim": o y -"1.' A separable attachment plug comprising a cap having binding screw s and contact posts, a base having, a screw shell, contacts in said base, brackets by which'said. conretained in' lace by the screw-shell and the se'cfondbrac et serving asa-center contact l with a socket, a screw by which said-second bracket retained in place, and-an insulat- I base.

ing guard disk intermediatefthe cap and. the

. 2. In a separable attachment plug, the a combination with a cap having a recess and binding screws and contact posts secured therein, of'an insulating ard disk covering the recess and detacha 1y secured to the contact posts. v

'3. In a separable attachment plug, the combination with a cap having a recess and binding screws and contact posts secured therein, of an insulating guard dlSk cover- 

